The primary objective will be to develop and apply in vivo techniques for evaluation of the somatic and mutagenetic effects on human cells of exposure to pollutants found in the environment. Human and mouse bone marrow and peripheral blood cells will be grown in diffusion chambers (DC) implanted in the peritoneum of host mice. Host animals will be exposed to environmental pollutants via several routes, e.g. intraperitoneal, intravenous, gastrointestinal and lungs. Cytogenetic analysis for chromosome aberrations (CA) and sister chromatid exchanges (SCE) will be made on the cultured cells and the bone marrow of the host animal. Comparison of these results will validate the DC findings to be representative of what happens in situ in the marrow of the host animal. As a measure of toxicity, the bone marrow of the host animals will be evaluated for total cellularity and hematopoietic stem cell content. Identically exposed animals will be tested for induction of dominant lethal mutations (DLM). Comparison of CA, SCE and DLM results will yield information on the relative sensitivity and usefulness of these systems for mutagenicity testing of environmental pollutants.